Alright so I found a link to a Reign of Gaming article that details a number of the changes on PBE (there appear to be some bugs concerning Jayce's E's tooltip as of now). Since it isn't Riot's official changes I'd take these with a grain of salt:

Some of the things of interest to note that aren't detailed in Phreak's PBE preview are: the new weapons (some for the revamped Twisted Treeline), new Galio splash art, Bonetooth necklace nerf and the stats on Elise (the new Spider champion).

I'll update with any major typos that the Reign of Gaming articles have (NOT with all of the changes):